Ch 16.1 Electric Charge and Static Electricity Electric charge: – Fundamental force of electromagnetism … magnets make electricity and electricity can.
Post on 29-Dec-2015
Ch 16.1 Electric Charge and Static Electricity
Ch 16.1 Electric Charge and Static ElectricityElectric charge:Fundamental force of electromagnetism magnets make electricity and electricity can make a magnetWe dont know whyit just doesits one of 4 forces that run science: gravity, em, strong and weak nuclear.Can be positive or negativeLike charges repel (push away), opposite charges attractElectric chargeWhere does the charge come from?Atoms have positive (protons in nucleus) and negative parts (electrons in orbitals)The electrons, because they are on the outside of the atom, can move from one atom to another or even one object to another!e.g. balloonMeasured in CoulombsMoving electronsThree ways can move from 1 object to anotherFriction: rub them off, e.g. balloon on hair, feet on carpetContact: touching a charged object to a non-charged one, e.g. sticking balloon to a wall, get zapped when touch metalInduction: bringing object close to non-charged, balloon and water.Moving electronsSoWhen you rub a balloon on your head (friction)Electrons move from your hair to the balloon and the balloon becomes negatively chargedYour hair becomes positively charged and sticks up because those charges repelAs the balloon gets closer to the wall (induction)The walls electrons are repelled and the surface becomes positively chargedThe balloon sticks because opposite charges attractMoving electronsCan also move within an single object is a conductor.Metals make good conductors because they have lots of valence electrons to loseIf the substance does not allow movement of charge, it is called an insulator.Nonmetals make good insulatorsElectric ForceThose attractions and repulsions are electrical forcesThe amount of force between two objects depends on:Amount of charge (directlymore charge = more force)Distance between charges (indirectlymore distance, less force)Electric ForceDoesnt have to be touching!Electric force is a field force, commonly drawn with lines going in to negative and out of positive